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Home > Sleep Research > The Stages of Sleep Each and every night, your brain passes through five stages of sleep. Passing through all these stages takes about 90-110 minutes and marks one full sleep cycle. So, if you sleep soundly for eight hours per night, you're getting five full sleep cycles. The Five Stages of Sleep
Stereograms are 3D images hidden within another picture. In order to view the 3-D images, simply stare at the picture until the image starts to take shape. See our Tips for Viewing Stereograms if you are having trouble seeing any of these images. All stereogram images contained within these galleries are used with the consent of the respective artists/authors. These images are copyrighted and cannot be used for any purpose except with the written permission of the artist/author. <p style="text-align:right;color:#A8A8A8"></p>
Who is more attractive as a mate? A guy who is kind or a guy who is cruel? A guy who is sensitive or a guy who lacks empathy ? A guy who is physically attractive or a guy who is homely? A guy who can appreciate art or the guy who only appreciates ESPN? Now consider who is more likely to be gay.
It is natural to believe in God, so more intelligent individuals are more likely to be atheists. Religion is a cultural universal, and its practice is observed in every known human society. However, as I explain in earlier posts (Why do we believe in God?
This page illustrates that our visual perception cannot always be trusted. The components of an object can distort the perception of the complete object. Our mind is the final arbiter of truth. Most optical illusions are the result of 1) incongruent design elements at opposite ends of parallel lines, 2) influence of background patterns on the overall design, 3) adjustment of our perception at the boundaries of areas of high contrast, 4) afterimages resulting from eye movements or from kinetic displays, or 5) inability to interpret the spatial structure of an object from the context provided by the picture. Optical illusions have been studied for millenia.
More Java applets here . If your browser supports Java , you should see an animated image above (generated by a Java applet embedded on the page). Otherwise, you should see a static image. Instructions for Viewing the Illusion: Sit about 50 cm (20 inches) from the screen. Look at the center of the spiral for about 20 seconds.
By Daniel Pouzzner, 2000-Apr-11/12 Sexuality is an indispensable mechanism whereby biological evolution bridged the immense gap between asexual/Lamarckian unicellular organisms, and the now plainly preeminent humans. For tens of millions of generations, the lineage leading to humanity has been formed and continued exclusively by sexual procreation. The precise microbiological mechanics of sexuality vary widely from species to species, while the functional consequences - strictly sexual procreation, in which each individual has precisely two parents, each contributing roughly half of the individual's genome - is absolutely conserved.
The ancient sages have set the foundations. The great minds included below have done the rest. Some have contributed more than others, but they have all had a major impact on their time, and hence on the generations to come. The Time Machine is not only showing the progress of humanity, but is itself a work of art in progress. If you know of someone important to the development of human consciousness who is not yet included, let us know ! Enter the Time Machine of the last 20 centuries , observing the progress of humanity and consciousness through time, specifically through the influence and impact of individual people.